Water arch



R. G. SEAIVIAN.

WATER ARCH. APPLICATION FILED MAY 7, |920.

Patented Apr. M., 1922.

NVENTOR ATTORNEY statt-l5 ROBERT GARDNER SEAMAN, OF SUMMERHILL, 'LDENNSYLVNA.

WATER ARCH.

Specification of Letters Patent.

aftented Apr, 11, 1922,

Application filed May 7, 1929. Serial No.V 379,599.

State of Pennsylvania, have invented new and useful Improvements in later Arches,

' of which the following is a speciication.

This invention relates to a water arch for a steam boiler furnace, and the Objectis to provide for La more effective distribution o of the heat units, and especially of the heat generated near the forward portion of the fire box of a locomotive boiler. y

' Certain Vtypes of arches, for effecting a similar purpose, are described and claimed in my Patent No. 1,346,769, datedl July 13, 1920, and in my application Serial Number' 202,547, liled November 17, 1917, and in the present application there will be described and claimed a type'of apparatus, or of arch, which includes an upper series of concentric tubular elements, .and a lower` series of concentric n tubular elements, the inner v tubes 'in -eachinstance serving toconduct or convey the heated gases from the forward portion of the fire box, upwardly and rearwardly to a point where they pass from the passages of the archand mingle with the currents passing from the other end of the fire box directly over the water arch, and thence through the tubes of the boiler. The tubes surroundingathetubes above referred to, are connected with the water jacket of the fur nace, and the temperature of the water in the outer tubes is ofcourse materially increased as the result ofthe passage of the `gases through, the inner tubes. Moreover, a passageway for the heated gases is provided between the upper and the lower series of concentric tubesand the upper tubes are-'covered with a layer of refractory material, retaining a considerable quantity of heat and giving it off after the maximum has been reached, and the ire over a portion of the grate surface has died downto a certain extent.

The invention contemplates the provision of a water arch which'shall includea head with a water compartment within the walls thereof, such compartment having connection with the water jacket of ax furnace, a plurality -of series of concentric tubes, mounted ,as above indicated and terminating within the head, and an element of particular construction connected with and forming a part of the arch and the lou'erforwaid end thereof, permitting` the heated gases to enter the inner tubes, and affordinga water connection with the outer tubes.

ln the accompanying drawings,

Figure 1 is a vertical longitudinal sccq tion through the furnace and through the water arch,

Figure 2 is a sectionon line 2-2 of Figure 1,

Figure 3 is a section on line 8 3 of Figure 1,

F i gure l is a view in perspective of the elements connected with the lower ends of the tubes of the arch;

' ln carrying out my inventioml provide a furnace structure including an upper and outer wall 10, and an inner wall 12 providing aiwater compartment 111. rlhe tube sheet is shown at 15, the fire tubes of the boiler being designated 16, and the'upper and klower tubesbeing of the relative size indicated. f

The head 18'of the arch extends the full width of the lire box, and includes a water compartment 21 having connection with the pipes'22 and 23 extending verticallyand hav-v ingcommunication with the water compartment above the fire box. This head also provides a compartment 25 through which the rheated `gases pass fromthe arch into the upper portion of the re box, Openings in. the double wall of the head "oppositethe tire door are closed by means of plugs such as 26.

The lower portion of the arch consists of a casting of the form shown in Figure 4L having communication with the water. jacket of the fire box yby means of elbows suoli as 29. This casting is designated 80 and provides a water chamber 31 havingcou'imunication with the water tubesA of the arch. These tubes are in two series, termed an upper and lower series, and the two series are spaced apart to provide an intervening passageway 34 through which the heated gases may pass from that portion of the fire box adj acentthe tubes of the boiler, in the direction shown by the arrows, and thence into chamber 25 of the head of the arch, emerging through passageway 25 and passingthence through the upper portion of the fire box where they are further heated by passing over the upper surface of the arch, assuming that at a given time the fire over that surface of the grate near the lower end of the arch has died down slightly, and that the the fire box.

upper surface of the arch still maintains a temperature approximating that to which it was previously heated.

' rlhe inner tubes; 33 also pernut of passage of heated gases, the current emerging from these tubes taking the same course through the' head and the upper Dertien of i3 i. i\. i

reduced, as shown, and enter apertures pri vided in the lower casting Bf) in the head. The lower ends of the inner tubes areconv nectedwith casting 30 in the manner shown,

the upper ends however'being'secured by apertured plugs designated 33. Irlhe water jacket of the head is in communication with the water compartment in the side walls of the furnace, by means of elbowsJ shown at 40.

By employing this'construction, especially Veffective results are realized, and the danger1 of injury to the tubes of ducedto a minimum. Y

Aswill be inferred from the foregoing, an important feature of the archy is the covcring for the upper series tubes. This covern Vthe boiler is re- 'ing is shown at 42, and is of the materialbest suited to thel purpose, the layer of material extending the full width of the arch,

and therefore the full width of the fire box,l as shownin Figures 2 and 3. l i l When a locomotive equipped with a superheating apparatus is under steam and running under load, the dampers of the super- Y heater are open and the hotY gases flow over boiler, said arch comprising a lower trans` `verse element,'an upper transverse element .the surface ofthe lire brick covering of the water arch and into all Yof thejtubesof the boiler, vetthe Sametime heatlng'the lire' the tubes, preventing a sudden change oftemperature. whichtends to cause contrac-V tion of the flue sheet andto produce leaks .between that sheet and the ends of the tubes. .rlhesedifliculies are reduced to a minimum,

or eliminated, in the'present construction.

VWhat I claim 1s l. The combination with a furnace strucl Vture includingeXterior walls providing ,a .water ]acket, of a water arch, and means for effecting communication between the water jacket and arch, said arch directing` gases' rearwardly through the fireboX and thence forwardly over the arch to a tubular constituting ahead, a series of tubes connectf ing the lower transverse: element with the head and permitting the passage there- T he ends of the outer tiiliais-arer led gases, respectively, from the lower forward portion ofthe arch to the interior of through of heated gases, and tubes surrounding those first named, and having-communication with the water jacket of the furnace, through said head.

lEZ. The combination with a furnacestructure the exterior walls of Vwhich provide a water jacket, cfa water arch inclined upwardlyfrom the lower forward Vportion 0T" 'the rebox of the furnace to a point beyond the middle portion of the fire box, saidV archA 7 5 directing gases rearwardly through the Vlirebox and thence forwardly over the arch to a tubular boiler,l saidarch including a head extending transversely'and providing there in a water compartment and a chamber for heated gases, the water compartment having communication with the water vjacket of the furnace, and parallel and concentrically arranged ducts for conducting water and heatthe' aforesaid head. Y

3. The combination with a furnace struc-k ture including a rebox and including waterV legs formed in the's'ide walls of the furnace, 90 of a water arch having communication Vwith the water legs, said arch directing vgases rearwardly through the reboX andtheme vforwardlyoverthe arch toa tubular boiler,

and comprising an upper and a lower series of concentric tubes, theinner tubes of each series lhavingn` their lowerends opening at the lower forward. portion of ",thei`flrebox,

a head for'ithe arch, the upper ends of said tubes opening into Vthe head, permitting -gases to pass fromv thel tubes through the head into'the iireboX 'above the arch, and the remaining tubes having communication with the water. legs throughthe interior` of the head. p f. I 105 4;.- The combination with a furnacestru'cture including water legs formedin the side walls thereof, of a'waterarch positioned in the lrebox of the furnace, extendingtrans versely ythereof between the side walls of the 11e i lireborf` and inclined downwardly toward the lower tubes yof the boiler, said arch including a plurality of concentrically arranged tubes forming an upper series, andv y similarly arranged tubes forming a lower series, a passageway beingprovided, between Y the two series, said arch also including" a head and a lower transverse element, said lower element and head being in oommunication with the interior of the tubes, and .per- Y mitting Oft-he circulation-of water and of heated gases, the latter passing fromlthe lower forward lportionoffthe arch tothe upper rear A`portion thereof, y andk the gases passing thence over4 the top of'therarch,and 125 a layerof heat absorbing material above the upper series of tubes. 'y 2, i, v

" 5. A wat-en "znchI for avboiler furnacecom-j l prisinga head formed with double walls pro` vidng a water space, a lower transverse element formed with double walls providing a water space, a series of tubes in parallel relation and having communication with the water spaces, and tubes positioned within those first named, extending beyond the ends thereof, through the water spaces, for conductingV heated gases from the lower exterior end of the arch to the upper end of the arch, the walls of the head dellecting the gases thence ovei` the arch, and a covering or" heat absorbing material for the tubes.

6. A water arch for a boiler furnace comprising a head formed` with double walls providing a water space, said head also providing an inner chamber, a lower transverse element having a water space therein, a series of tubes each having communication 'with the water spaces. tubes within those lirst named and extending; through the water spaces, the lower ends of the tubes opening exteriorly' of the arch, and the upper ends opening into the inner chamber of the head, additional tubes spaced from those aforesaid and providing a passageway therebetween opening into the head, and a covering` of heat absorbing material for the arch.

In testimony whereof I affix my signature,

ROBERT GARDNER SEAMAN. 

